Many beverages sold today at amusement parks, by street vendors and in drugstores utilize crushed ice in combination with other ingredients providing a flavorful drink. In other instances, the beverage might include soda water, sparkling water, or equivalent fizzy mediums which cause generation of foam or a "head". Often when a beverage is rapidly mixed, a foamy type "head" will develop.
While such "foamy heads" are fairly cohesive, where crushed ice forms a part of the foamy beverage, the substance will invariably spill over the rim of the cup. It is difficult to control this spillage since the foamin action continues to occur even after the pouring of the beverage in the cup has stopped.
It would be very helpful if some means were available to inhibit such spillage of a beverage over the cup rim without appreciably adding to the cost of the beverage and without detracting from the overall appetizing appearance of the beverage in question.